I bought a 98 Ram 1500 4x4 SLT for my daughter little over a year ago. When I purchased it the dealer said the transmission had been rebuilt shortly before that. Yesterday the truck started suddenly shaking when driving was worse of course at faster speeds. I thought well maybe she had somehow hit the 4x4 and got it out of gear so I put it into 4L and then back into 2H. It seemed to do a little better at slow speeds at first but after getting up to about 45/50 MPH it started shaking again. When it starts it tends to stop shaking when you put it into neutral or as to let off the gas. Any ideas of what the issue may be? Thanks for any help you can give I don't know anything about mechanics.

 

does it do it religiously every time or is it at random times? Someone might correct me if I'm wrong but sometimes at those speeds when it drops into overdrive, if you have an engine misfire it can cause the truck to shake like that. Any check engine lights? Another possibility would be the death wobble but I'm not sure if that goes away if you let off the gas or put it in neutral, I believe that's more speed related. Someone will chime in with a better idea of what it could be.

 

Sounds like a misfire to me.

Take it out on the road again and push the OD Off button on the gear selector and see what happens.

 

Death wobble? What is that ..doesn't sound good. It is vibrating hard...shaking really bad. It just happened for the first time yesterday. I will try the other suggestion later today after work. Thanks.

 

Death Wobble is where the track bar on the front axle has worn out bushings and it allows the front end to shake back and forth if you hit a bump at speeds above 45 mph.

I don't think you have Death Wobble though, personally. I think you have a misfire.

 

Gonna jump on the misfire bandwagon here. Probably be good to check the plenum. Have a read thru the stickied thread at the top of this forum.

 

Sounds like misfire to me as well. Change your plugs and see if that doesn't help, if so, time to figure out what caused the plugs to foul.
Do as HeyYou says and read that plenum thread. Problems tend to snowball on these engines and a leaking plenum gasket is usually the main culprit.

 

Check the u-joints also. I had a truck years ago that did similar, the u-joints were the cause of it.

 

Did she loose a wheel weight? Look for a dirty spot where one used to be on the wheels.

Sounds more like death wobble or a bad U joint to me though.

First thing I would check would be the Ujoint at the rear differential. Check the Straps and pinion yoke also.

Second would be death wobble which can be caused by worn steering or suspension components. Check all of the steering joints. If all seems fine jack on front wheel at a time and try to pulling and pushing on the wheel at 12 and 6 oclock looking for worn baljoints.

 

Check to make sure the tires are round. I had a bulge form about a month ago, caused the same trouble. $207 for a new tire and everything is fine.